Question about generic swing JFrame structure

Hi,
I have a number of JFrames within an application and I'm to promote re usability by being easily able to add panels to these JFrames to cause the least disruption to users. There is a common panel across all JFrames and it is the bottom panel with a connect and exit button. I have a problem though. Say within a JFrame, I have 2 panels, 1 with a number of textfields that must be validated and the other panel is the bottom panel. I perform my validation in the bottom panel using the start and stop buttons. I tried to make the bottom panel generic and place the validation code in the textsfields panel. But when I called the validation code from the bottom panel which resided in the textfields panel, the validation code knew nothing about changes to the textfields, therefore at this stage, I presume the validation code must reside in the Jframe itself. What I would like to know now is, if I make a panel within JFrame(s) generic, how can I call the validation code from the generic JPanel which resides in the JFrame and is this my only possibility. This is just a private project, any help appreciated.